US3555306A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Keyboard sprocket circuit
Assignee: Momentum Systems Corp
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Filing: 1969-01-14
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Granted: 1971-01-12
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Expires: 1989-01-14
Abstract
Abstract A pulse-shaping circuit for converting a signal from an operator controlled keyboard to one which is free of bounce-spikes and suitable for logic circuits in a data recording machine. The circuit contains a pair of integrating networks which reshape the leading and trailing edges of the keyboard output signal. Additionally, if the keyboard output occurs for a predetermined length of time, the circuit provides a continuous series of signals for repetitively recycling the machine as long as the keyboard output signal remains. This is accomplished by a timing circuit, responsive to such a keyboard output, which activates a circuit for transmitting repeated simulated keyboard outputs to the pulse-shaping circuit. The timing and simulation circuits are connected in a feedback delay loop to cause the pulse-shaping circuit to oscillate at a fixed frequency.
Inventors
- 👤 George R Cogar
- 👤 Torkjell Sekse
- 👤 Walter Banziger
- 👤 Joseph W Ming
- 👤 Laszlo Horvath
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:30
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/14; G06F11/1497; G01; G01R; G01R29/00; G01R29/02; G01R29/027; G01R29/0273; G06F11/16; G06F11/1608; G06F11/1616; H; H03; H03K; H03K17/00; H03K17/16; H03K21/00; H03K21/08; H03K3/00; H03K3/01; H03K3/013; H03M; H03M11/00; H03M11/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
664 words
In a data recording machine of the Character described including a keyboard, a keyboard sprocket and automatic repeat circuit comprising: an input and an output terminal, the potential at said input terminal being switchable from a low to a high state by the actuation of a keyboard switch, a plurality of diodes the anodes of which are connected to a common point, said input terminal being connected to the cathode of one of said diodes, the input to the cathodes of the other diodes all being at a high potential, a first transistor, a resistor connected between the common point of said diodes and the base of said first transistor, said input terminal supplying current to said transistor through said resistor whereby the transistor is made conductive when the circuit is in its quiescent state, a second and a third transistor each of which is nonconductive when the circuit is in its quiescent state, said second transistor having its emitter connected to the collector of said first transistor and its collector connected to the base of said third transistor, the base of said second transistor being connected to the collector of said third transistor, the collector of the third transistor also being connected to said output terminal, the emitters of said first and third transistors both being connected to a point of reference potential, a first capacitor connected between the collector of said first transistor and said point of reference potential, said capacitor being discharged when the circuit is in its quiescent state, said input terminal being switched to a high state upon closing a keyboard switch causing said first transistor to become nonconductive and said capacitor to start charging, said second transistor being rendered conductive when said capacitor charges to the same potential as that of the collector of said third transistor whereby the second transistor supplies current to the third transistor making it conductive also, the reciprocal base-collector connection between said second and third transistors causing heavy feedback between them whereby the collector of the third transistor switches from a low to a high state and said output terminal is supplied with a spike free signal for generating a keyboard sprocket; a fourth transistor having its base connected to the collector of said third transistor, a second capacitor in said last-named base to collector connection, a fifth transistor having its base connected to the collector of said fourth transistor and its collector connected to the cathode of one of said diodes that is not connected to said input terminal, the emitters of said fourth and fifth transistor both being connected to the point of reference potential, said fourth and fifth transistors each being conductive when the circuit is in its quiescent state, said fourth transistor being rendered nonconductive when the collector of said third transistor switches to its high state, means to supply drive current to said fifth transistor to keep it conductive when the fourth transistor becomes nonconductive, said second capacitor being caused to discharge when said third transistor collector remains in its high state beyond a predetermined period of time whereby said fourth transistor again becomes conductive and prevents the supply of further drive current to said fifth transistor, said fifth transistor being made nonconductive by the removal of its drive current whereby the input to the diode connected to its collector is switched from a high to a low state thereby providing the equivalent of a switch contact opening, and a third capacitor connected between the bases of said first and second transistors, the switching of the input to said last-named diode causing said third capacitor to be charged until said first transistor again becomes conductive whereby said second and third transistors become nonconductive and the collector of the latter switches to its low state causing an interruption in the signal supplied to said output terminal, said fifth transistor being again made conductive by the noncondUctive state of said second and third transistors whereby an oscillatory action is established.
Claim 2
Dependent Claim
664 words
In a data recording machine of the Character described including a keyboard, a keyboard sprocket and automatic repeat circuit comprising: an input and an output terminal, the potential at said input terminal being switchable from a low to a high state by the actuation of a keyboard switch, a plurality of diodes the anodes of which are connected to a common point, said input terminal being connected to the cathode of one of said diodes, the input to the cathodes of the other diodes all being at a high potential, a first transistor, a resistor connected between the common point of said diodes and the base of said first transistor, said input terminal supplying current to said transistor through said resistor whereby the transistor is made conductive when the circuit is in its quiescent state, a second and a third transistor each of which is nonconductive when the circuit is in its quiescent state, said second transistor having its emitter connected to the collector of said first transistor and its collector connected to the base of said third transistor, the base of said second transistor being connected to the collector of said third transistor, the collector of the third transistor also being connected to said output terminal, the emitters of said first and third transistors both being connected to a point of reference potential, a first capacitor connected between the collector of said first transistor and said point of reference potential, said capacitor being discharged when the circuit is in its quiescent state, said input terminal being switched to a high state upon closing a keyboard switch causing said first transistor to become nonconductive and said capacitor to start charging, said second transistor being rendered conductive when said capacitor charges to the same potential as that of the collector of said third transistor whereby the second transistor supplies current to the third transistor making it conductive also, the reciprocal base-collector connection between said second and third transistors causing heavy feedback between them whereby the collector of the third transistor switches from a low to a high state and said output terminal is supplied with a spike free signal for generating a keyboard sprocket; a fourth transistor having its base connected to the collector of said third transistor, a second capacitor in said last-named base to collector connection, a fifth transistor having its base connected to the collector of said fourth transistor and its collector connected to the cathode of one of said diodes that is not connected to said input terminal, the emitters of said fourth and fifth transistor both being connected to the point of reference potential, said fourth and fifth transistors each being conductive when the circuit is in its quiescent state, said fourth transistor being rendered nonconductive when the collector of said third transistor switches to its high state, means to supply drive current to said fifth transistor to keep it conductive when the fourth transistor becomes nonconductive, said second capacitor being caused to discharge when said third transistor collector remains in its high state beyond a predetermined period of time whereby said fourth transistor again becomes conductive and prevents the supply of further drive current to said fifth transistor, said fifth transistor being made nonconductive by the removal of its drive current whereby the input to the diode connected to its collector is switched from a high to a low state thereby providing the equivalent of a switch contact opening, and a third capacitor connected between the bases of said first and second transistors, the switching of the input to said last-named diode causing said third capacitor to be charged until said first transistor again becomes conductive whereby said second and third transistors become nonconductive and the collector of the latter switches to its low state causing an interruption in the signal supplied to said output terminal, said fifth transistor being again made conductive by the noncondUctive state of said second and third transistors whereby an oscillatory action is established.
Claim 3
Dependent Claim
23 words
A circuit as defined in claim 1 wherein said resistor and said third capacitor essentially comprise a turn off integrator for the circuit.
Claim 4
Dependent Claim
52 words
A circuit as defined in claim 1 including a second resistor extending from a point of biasing potential to the collector of said first transistor, said second resistor and first capacitor forming a turn on integrator for the circuit, said turn on integrator having a longer period than said turn off integrator.
Claim 5
Dependent Claim
121 words
In a circuit for controlling the operation of a system in response to actuation of a start switch wherein a pulse shaping circuit receives the output from said switch and generates a start signal substantially representative of the duration of actuation of said switch, the combination comprising: a timing circuit responsive to said start signal for generating a control signal a first predetermined period of time after initiation of said start signal; and a simulation circuit operable in response to said control signal for transmitting to the input of said pulse shaping circuit a series of signals simulating repeated actuations of said start switch, whereby said pulse shaping circuit generates a corresponding series of start signals to control said system accordingly.
Claim 6
Dependent Claim
121 words
In a circuit for controlling the operation of a system in response to actuation of a start switch wherein a pulse shaping circuit receives the output from said switch and generates a start signal substantially representative of the duration of actuation of said switch, the combination comprising: a timing circuit responsive to said start signal for generating a control signal a first predetermined period of time after initiation of said start signal; and a simulation circuit operable in response to said control signal for transmitting to the input of said pulse shaping circuit a series of signals simulating repeated actuations of said start switch, whereby said pulse shaping circuit generates a corresponding series of start signals to control said system accordingly.
Claim 7
Dependent Claim
50 words
The circuit set forth in claim 4 wherein said timing circuit and said simulation circuit are connected in a feedback delay loop between the input and output of said pulse shaping circuit whereby said circuit is caused to oscillate at a fixed frequency after said first predetermined period of time.
Claim 8
Dependent Claim
65 words
The circuit set forth in claim 5 wherein said timing circuit includes an integrating network to provide said feedback delay, said network being constructed and arranged to recover to a fully charged state between actuations of said start switch and to only partially recover between said fixed frequency oscillations whereby the period of said oscillations is substantially shorter than said first predetermined period of time.
Claim 9
Dependent Claim
329 words
In a data recording machine of the character described, a keyboard sprocket circuit comprising: a. an input and an output terminal, a first transistor that is conductive and a pair of additional transistors that are nonconductive when the circuit is in its quiescent state, said pair of transistors having reciprocal base-collector connections with one another whereby heavy feedback occurs when one of the transistors becomes conductive, and a resistor-capacitor turn on integrator and a resistor-capacitor turn off integrator cooperable with said transistors, said first transistor being rendered nonconductive and said pair of transistors being rendered conductive when a signal is applied to said input terminal in response to the closing of the contacts of a keyboard switch, said pair of transistors being operable in a conductive state to supply a signal to said output terminal for the generation of a keyboard sprocket, said signal being supplied essentially independent of the integrator periods due to the heavy feedback action between said pair of transistors; and b. a second pair of transistors connected in said circuit across said previously named transistors, said second pair of transistors being conductive when the circuit is in its quiescent state, means to render one of said second pair of transistors nonconductive when said first pair of transistors is applying a signal to said output terminal, means operable when said one transistor is rendered nonconductive to keep the other transistor conductive, means operable when a signal is supplied to said output terminal beyond a predetermined period of time to render the nonconducting transistor of said second pair conductive and the conducting transistor nonconductive, and means operably connecting said last-named transistor to said first three named transistors whereby said first transistor is again rendered conductive and said first pair of tranSistors nonconductive whereby the signal to said output terminal is interrupted, the nonconductive transistor of said second pair being made conductive by the nonconductive state of said first pair of transistors whereby an oscillatory action is established.
Claim 10
Dependent Claim
329 words
In a data recording machine of the character described, a keyboard sprocket circuit comprising: a. an input and an output terminal, a first transistor that is conductive and a pair of additional transistors that are nonconductive when the circuit is in its quiescent state, said pair of transistors having reciprocal base-collector connections with one another whereby heavy feedback occurs when one of the transistors becomes conductive, and a resistor-capacitor turn on integrator and a resistor-capacitor turn off integrator cooperable with said transistors, said first transistor being rendered nonconductive and said pair of transistors being rendered conductive when a signal is applied to said input terminal in response to the closing of the contacts of a keyboard switch, said pair of transistors being operable in a conductive state to supply a signal to said output terminal for the generation of a keyboard sprocket, said signal being supplied essentially independent of the integrator periods due to the heavy feedback action between said pair of transistors; and b. a second pair of transistors connected in said circuit across said previously named transistors, said second pair of transistors being conductive when the circuit is in its quiescent state, means to render one of said second pair of transistors nonconductive when said first pair of transistors is applying a signal to said output terminal, means operable when said one transistor is rendered nonconductive to keep the other transistor conductive, means operable when a signal is supplied to said output terminal beyond a predetermined period of time to render the nonconducting transistor of said second pair conductive and the conducting transistor nonconductive, and means operably connecting said last-named transistor to said first three named transistors whereby said first transistor is again rendered conductive and said first pair of tranSistors nonconductive whereby the signal to said output terminal is interrupted, the nonconductive transistor of said second pair being made conductive by the nonconductive state of said first pair of transistors whereby an oscillatory action is established.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-11 | 1974-07-13 | 1975-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-11 | 1978-07-13 | 1979-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-11 | 1982-07-13 | 1983-01-12 | $7700.00 | Window Closed / Lapsed |